Polarized relay



Aug. 19, 1958 J. L. RUSSELL POLARIZED RELAY Filed May 1, 1956 2Sheets-Sheet l Aug. 19, 1958 J. L. RUSSELL POLARIZED RELAY 2Sheets-Sheet 2 Filed May 1. 1956 FIG United State POLARIZED RELAYApplication May 1, 1956, Serial No. 581,984

13 Claims. (Cl. soc-93 This invention relates to electrically actuatedcontactors, especially contactors of the double-throw, polarized type.

In my copending application, Serial No. 515,373, filed June 14, 1955,assigned to the assignee of the present application, I have described acontactor of the polarized type which in common with relays of thisclass is characterized by its balanced design by which, in theunenergized condition, there is no greater tendency on the part of thedefiectable armature to occupy one position or the other, and commonlythe armature remains in the position in which it is left as determinedby the direction of the last current pulse to which the operating coilis subjected. In some uses, however, as, for example, for obtainingcontrol functions when applied in electron-tube circuits, a definiteposition of the armature is required when the operating current is at ornear zero. In the above-identified patent application, resilient biasingmeans were provided to obtain this type of operation, if desired.

I have found, however, that mechanical bias, while highly desirable forsome applications, is inherently limited in speed and efiiciency so asto leave much to be desired where enhanced speed and efiiciency arerequired due to the following considerations:

In obtaining optimum performance from a relay of this class, the ratioof force developed magnetically in the armature to the total Weight ofthe armature should be very high. This permits high values ofacceleration of the moving contact in switching from one position to theother which results in small values of switching time and,concomitantly, improvement in immunity of the moving system to shock andvibration. Actually, the said ratio is limited by (a) the value ofmagnetic flux which can be induced longitudinally in the armature,limited by the saturation density of the material of which it is made;and (b) the flux density in the air gap, limited by over-all size of thepermanent magnet structure, magnetic leakage flux, and other similarconsiderations. In the case of polarized operation, the operating-coilmagneto" motive force is usually made equal to or greater than the valuerequired to give an armature force corresponding to saturationconditions. This force is then reproduced in magnitude in the oppositedirection when the coil current is reversed. The force is at or nearzero when the coil is de-energized. Now, when relay action is desiredusing a D.-C. energizing current of on-off impulses instead of areversing current, the direction of this D.-C. current being of definitepolarity determined by the direction of the permanent field, thearmature may be biased mechanically as hereinbefore observed. Thisresults in a force avail-able in each direction of one half of thesaturation force, or the sum of forcesis equal to the saturation force.

In accordance with my invention by which I provide an unbalancing fluxpath diverted from the permanent field, the sum of the forces inrelay-type operation can be made to exceed the saturation. force and, infact, approach twice that force. The armature force for zero coilcurrent is derived from the field flux flowing in the armature ice whichmay approach the saturation value with corresponding value of force. Themagnetomotive force developed by the coil when operating current isapplied opposes this field flux and when fully developed overcomes thisflux to approach a saturation value of flux and force in the oppositedirection. Hence, the force-toweight ratio in this case approaches twicethat in the spring-biased case, with consequent advantage in speed ofoperation, design eificiency, and other desirable characteristics.

It is thus a primary object of this invention to provide anelectromagnetic relay having reduced armature transit time and improvedover-all immunity to shock and vibration.

It is a further object to provide a high-speed doublethrow relayadaptable to miniaturized design.

It is a still further object to provide an electromagnetic relay ofunbalanced magnetic field structure such that the deflecting force mayapproach twice the saturation force.

Further objects as well as advantages will be apparent from thefollowing description and the accompanying drawings in which Figure l isan isometric exploded view of the parts of a relay device embodying theprinciples of the invention;

Figure 2 is a vertical, cross-sectional view of an assembled devicewithin an enclosure;

Figure 3 is a sectional view through line 3-3 in Figure 2;

Figure 4 is a view similar to Figure 2 but rotated about itslongitudinal axis and contained within an enclosure of sealedconstruction with mounting base;

Figure 5 is a schematic drawing of the embodiment of the inventionillustrated in Figures 1 to 4, inclusive; and

Figures 6 and 7 are schematic drawings illustrative of other embodimentsof this invention.

Referring now to the drawings and to Figures 14 in particular, asupporting member 20 comprises a fiat, cylindrical base portion 21 andan axially disposed stem portion 22, integrally formed from one piece ofbrass or equivalent non-magnetic material of high thermal conductivity.The member 20 is formed with a central bore 23 extending through thebase portion 21 and penetrating the stem portion 22. One side of saidstem portion is of cylindrical curvature coaxial with that of the baseportion 21, and the other side is flattened to provide a plane surfaceparallel to said axis. The section of said stem portion is less than asemicircle so that the axis of the structure does not lie within thestem part, but is displaced from the plane surface by a small distance,the purpose of which will hereinafter be set forth. A radial slot 24(Figure 3), formed in the base portion 21 and extending from theperiphery thereof into the central bore 23, breaks the path of eddycurrents in the base member and provides access thereto for placing,inspecting, and adjusting small parts presently to be described.

Mounted upon the fiat surface of the stem portion 22, and extendingthrough the opening 23 in the base portion 21, is a member 25 formed ofsheet silicon steel or equivalent ferromagnetic material. As indicatedin Figure 1, the member 25 is paddle shaped, having a relatively broadbase part substantially the Width of the stem portion 22, while theextending part or tongue, forming a cantilever armature, is made narrow,of small inertia, and relatively stiff in construction. The previouslymentioned displacement of the plane surface of the stern portion 22 fromthe cylindrical axis is preferably half the thickness of member 25, sothat when assembled the center line of said member 25 will coincide withsaid axis. As fully set forth in my Patent No. 2,636,094, the materialof which the member 25 is formed need not be especially critical in itsmagnetic characteristics, the general requirement being the member 25and electrically insulated therefrom is adouble-faced contact member 26formed preferably of one of the alloys in the platinum group. This partof the assembly may readily be effected by forming the piece of contactmetal in a U-shape, inserting the extremity of the member 25 insulatedby small barriers of mica or the equivalent, clamping these componentparts into an integral assembly, and firmly securing them in place witha suitable cementitious material. Permanent electrical connection tosaid movable contact member is made by means of a flexible wire 28having one end soldered or welded to the member 26. Variablemagnetization of the member 25 is effected by means of a solenoid orcoil member 39 having an internal opening to slip over thesemi-cylindrical stem 22 and having a winding 31 adapted to carry thecurrent to which it is desired that the movements of the member 25 bemade responsive.

The magnetic structure whereby there is provided a permanentunidirectional field wherein the free tongue portion of the member 25may operate as an armature comprises a pair of T-shaped soft ironassemblies 35 and 36, preferably of laminated construction, the stems ofthe Ts constituting polar projections oppositely and inwardly directedto form an air gap 37. The outer arms of the assemblies 35 and 36 arebridged by permanent magnets 39 and 40 so disposed that each T-shapedassembly makes contact with similar poles of the two magnets. Thus, asshown in Figures 1 and 3 of the drawings, the north poles of bothpermanent magnets are in contact with the assembly 36 and the southpoles with assembly 35, so that flux in the air gap 37 may be consideredas passing from right to left as seen in Figures 3 and -7.

A shunt path for said permanent field flux is provided by L-shapedmember 27 which is disposed at one end to make contact with the armature25 by being secured with it to the stem 22 as by screws. It extendsalong the outer contour of coil 31 and terminates at or near thepermanent magnet assembly 35. As shown, this member is separatedslightly from the pole 35 to form a variable reluctance in the magneticcircuit. The shunt member is formed of thin sheet, ferro magneticmaterial and may be preformed, or bent to conform to requirements afterassembly.

When the device is assembled with the members 25 and 27 mounted upon thestem portion 22, the coil 30 surrounding said stem portion is broughtinto close engagement with the. corresponding face of the base portion21 of the supporting member 2%). The broad base part of theferromagnetic member 25 extends substantially along the axis of saidcoil, providing an optimum path for the flux in that part of themagnetic circuit. The magnetic structure comprising the assemblies 3536and the magnets 3940 rests against the opposite face of the base 21,being secured in position by means presently to be set forth. The tongueportion of the member 25 extends through the opening 23 and lies withinthe air gap 37 with its contact-bearing portion projecting therebeyondand adapted for coaction with stationary contact members now to bedescribed.

Positioned against the faces of assemblies 3536 on the sides remote fromthe base 21 is a massive metal supporting block 41, of U-shape, asindicated, and insulatedly carrying stationary contact members 43 and44, juxtaposed to opposite faces of the movable contact member 26 andadapted to be alternatively engaged thereby as the latter member ismoved back and forth with motion of the movable member 25. Each of thestationary contact members 43-44 takes the form of a thin, fiat strip ofresilient contact metal formed basically to an L-shape with one armextending across the face of the corresponding arm of the U-shaped block41 and terminating in a loop portion adapted for connection of aconducting wire. The other arms of the L- shaped contact members extendsubstantially parallel to the axis of the main assembly, one on eachside of the movable ferromagnetic member 25, and each has a tip portionangularly bent inward to be juxtaposed to, and engaged by, the movablecontact member 26. The tip portions of the contact members 43--44 arepreferably bifurcated, as indicated in Figure 1 whereby to reduce theprobability of failure to complete the circuit between the stationaryand the movable contact members should a particle of non-conductingmaterial find its way onto a contact surface. For reasons to be relatedhereinafter, in the structure shown and with no operating currentapplied, the armature 25 is permanently but resiliently defiected towardthe north pole formed by the projection of member 36, and the attachedcontact 26 thus makes contact with fixed contact 44.

Extended screws 45, coacting with suitable clamping and insulatingplates positioned opposite either face of the transverse portions of thecontact members 4344, pass through openings formed in the block 41,straddling the polar projections of the assemblies 35-36, and engagethreaded openings in the base portion 21, whereby, when tightened, tosecure and clamp into an integral unit said base portion, magneticstructure, supporting block, and stationary contact members. Theconformation of the laminated parts of the magnetic structure is madesuch as to allow appreciable clearance around the screws, thusfacilitating lateral adjustment, and exact centering of the air gap 37,as assembly is effected.

Adjustment of the stationary contact members 43 and 44 toward and fromthe movable contact member 26 is effected by means of screws 47 and 48transversely threaded through the respective arms of the U-shaped block41, on a common axis, and provided with insulating tips adapted to bearupon the outer faces of said movable contact members and force them moreor less toward the center line of the structure, according to theadjusted setting of said screws. With a view to eliminating organicmaterial from the assembly, the insulating tips of the screws 47 and 48may expediently be formed of spherical glass beads spun into recessesformed in the extremities of the screws.

As hereinbefore pointed out, connection between the movable contact 26and stationary parts of the external circuit is effected by means of awire 28 having one end attached to said contact. The other extremity ofsaid wire is secured at a terminal lug 52 which is insulatedly supportedby means of a screw 51 threaded into the yoke portion of the U-shapedblock 41.

The apparatus, as thus far described, is enclosed in a cylindrical shellor casing 55 having a closed end toward which the extremity carrying thecoil 30 is inserted and, at the other end, being provided with ascalable closure 56 (Figure 4), carrying insulated terminals, preferablyadapted for plugging into a conventional socket such as is used withelectronic equipment. One of said terminals is connected to the forkedmember 52 by means of a wire 58 and, thus, to the movable contact 26.Two of the remaining terminals are connected to the contact members 43and 44 by means of wires 59 and 60, respectively. Further terminals, notappearing in the drawings, are connected by means of leads 61 and 62shown in Figure 2) to the winding of the solenoid 30, thus providingcomplete electrical connection between the switching device and externalcircuits and permitting hermetic sealing of the assembly if desired.

Hermetic sealing not only serves to exclude moisture and objectionableatmospheric contaminants from the sensitive contacting surfaces of thedevice, but also renders it possible more or less to evacuate theinterior of the casing or to surround the contacts and other electricalparts with an artificial atmosphere of any desired composition orpressure. By the use of suitably selected inorganic insulating media, itis possible to exclude from the enclosure certain undesirable vaporsknown to emanate from some organic materials.

The shell of casing 55 may be of magnetic or of nonmagnetic material,according to alternative operating principles presently to be set forth.As indicated in Figures 2 to 4, inclusive, which represent a practicalform of the apparatus, in particular the shell 55 may be consideredeither ferromagneticor non-ferromagnetic, since its effect on themagnetic circuit, if any, may be readily compensated for by adjustablemagnetic means to be described.

In considering the operation of this device as a relay normally biasedwith one contact closed, attention is directed to Figure 5 which:is aschematic representation of the essential elements and theinterrelationships thereof of the embodiment of my invention illustratedin detail in Figures 1 to 4. Herein a single permanent magnet 106 forsimplicity is made to' correspond to magnets 39 and 40 of the detaileddrawings, Figures 1 to 4; the field pole pieces 104105 correspond to 36and 35, respectively; stationary contacts 102 and 103 correspond to 44and 43, respectively; armature and solenoid 101 and 100 represent thecorresponding elements 25 and 31; shunt member 110 refers tocorresponding member 27; enclosure 111 refers to outer shell 55.Conforming to the description hereinbefore related, the armature isshown fixed at one end in a position which includes the longitudinalaxis of the structure. The other, or free, end of the armature 101 isdeflected, under the influence of the shunt magnetic member 110, towardthe north pole. The movement-of the armature is limited by the fixedcontact 102 with which it also makes electrical contact.

The magnetic structure comprising the ferromagnetic assemblies 104 and105 together with the magnet 106 provides a-permanent field in the gap112 wherein is disposed the movable tongue of the ferromagnetic member101. While the main flux of this field will flow transversely oftheshort section of the member101 lying within the gap 112, there will be adiversion of flux through the armature member 101, due to. shuntmember110, thus causing permanent longitudinal magnetization of the armature.The above-described disposition of elements produces the path ofpredominant flux indicated in Figure 5 by a broken line. In effect,therefore, a biasing magnetic force is exerted on the armature 101which, in the absence of other magnetic forces, pulls said resilientarmature against contact member 102. The magnitude of said biasingmagnetic force is dependent on the actual dimensional values of the airgaps in the magnetic circuit, since such values predominantly determinethe overall reluctance of the magnetic path. Practically, these valuesare kept to a minimum to assure positive and reliable biasing withoutaffecting dynamic operation of. the relay as hereinafter described. Theair gap shown between the shunt member 110 and the pole piece 105 isintended to provide practical means for adjustment of the. optimum valueof shunted flux to obtain desired operation.

In operation, the winding 100 is energized preferably by on-oif impulsesof direct current. The polarity of the applied current must be such asto produce a magnetic field which will pass longitudinally of member 101and in a direction opposed to the above-described biasing flux of thepermanent magnetic field. For any one pulse of operating current, saidflux due to the operating coil will increase in magnitude until thebiasing. flux due to the permanent magnet is neutralized, whence thetongue of armature 101 is released from contact 102 and, through furtherincrease in magnetomotive force, is urged toward the'S-pole piece 105,thus making contact with contact member 103. Upon interruption of theenergizing current, the field flux diminishes until the magnetic forcedue to: the permanent magnet 106 and the'resilient force of the tongueitself cause its release from contact 102 and movement toward the N-poleof member 104. Because the permanent biasing flux predominates overinherent mechanical forces in the rigidly supported armature member 101,the tongue portion of said member is then caused to deflect further inthe direction of the N-pole until contact is made with contact 102. Ineffect, therefore, the relay operates. as a magnetically reversibledevice energized by an unidirectional impulse.

It is recognized that the principles of my invention can be extended toother modifications of the structure hereinbefore described. Forexample, in Figure 6 is shown a structure which is the same as thatdescribed in connection with Figure 5 except that here the enclosingshell has been omitted and the shunt path closed at both ends. A fixedarm 109 of ferromagnetic material joins the fixed end portion of thearmature to S-pole piece 108. Though this arrangement may be preferredunder some practical conditions, the principle differs in no respectfrom the hereinbefore described embodiment.

In Figure 7 is shown a further modification in which case the fixed endof the armature 101 does not lie in the center line of the structure butis displaced to one side or the other of the axis. In this case, thesymmetrically disposed enclosure 107 must be of a ferromagneticmaterial, since it forms a return path for field flux. The dissymmetryof the armature structure produces the permanent longitudinalmagnetization and the flexible part of the armature 101 is attractedtoward N-pole 102 and thus causes engagement, under static conditions,with contact 102. The path of predominant flux is shown by the brokenlines. In all other respects, the operation is as hereinbeforedescribed;

It is to be noted that the devices shown in Figures 6 and 7 may beconstructed as was described in detail in connection with Figures l-Sexcept for those distinguishing features which have been pointed out inconnection with Figures 6 and 7.

Theterms and expressions which have been employed are used as terms ofdescription and not of limitation, and there is no intention in the useof such terms and expressions of excluding any equivalent of thefeatures shown and described or portions thereof, but it is recognizedthat various modifications are possible within the scope of theinvention claimed.

I claim:

1. A polarized relay, comprising means including a polar structuredefining a gap and for producing a constant magnetic field in said gap,a movable contact, a pair of stationary contacts each adjacent to and inposition to be engaged by said movable contact upon displacement of thelatter through an intermediate position, magnetic circuit meansindependent of said first mentioned means and including a deflectablearmature extending in said gap for shifting said movable contact betweensaid stationary contacts, said magnetic circuit means having a portionthereof remote from said gap positioned in close proximity with saidpolar structure and including said gap in common with said polarstructure and being adapted to shunt the flux path across said gapasymmetrically and thereby bias said armature to maintain said movablecontact normally in engagement with one of said stationary contacts, andmeans for producing a magnetic field flux along said armature in adirection opposed to the flux of said constant magnetic field wherebysaid armature is deflected to shift said movable contact away from saidone stationary contact and into engagement with the other of saidstationary contacts.

2. A polarized relay, comprising means including a bipolar structuredefining a gap and for producing a constant magnetic field insaid gap, amovable contact, a pair of stationary contacts each adjacent to and inposition to be engaged by said movable contact upon displacement of thelatter through an intermediate position,

magnetic circuit means-independent of said first mentioned means andincluding a deflectable armature extending in said gap and supportingsaid movable contact for displacement between said stationary contacts,said stationary contacts each being positioned on a side of said movablecontact corresponding to one of the poles of said polar structure, meanssupporting said armature for deflection in said gap toward the poles ofsaid polar structure in response to the net effect of the magnetic fluxtraversing said armature, said magnetic circuit means having a portionthereof remote from said gap positioned in close proximity with saidpolar structure and including said gap in common with said polarstructure and being adapted to shunt the flux path across said gapasymmetrically and thereby bias said armature toward one of said polesto maintain said movable contact normally in engagement with one of saidstationary contacts, and means for producing electromagnetic field fluxalong said armature in a direction opposed to the flux of said constantmagnetic field whereby said armature is deflected toward the other oneof said poles and engages said movable contact with the other one ofsaid stationary contacts.

3. A polarized relay, comprising means including opposed polarstructures juxtaposed to provide a gap and for producing a substantiallyconstant magnetic field in said gap, support means, magnetic circuitmeans independent of said first mentioned means and including aferromagnetic member fixed to said support means and having a resilientarmature part extending in said gap free for displacement toward eitherof said polar structures, a first contact carried by and movable withsaid armature part, a pair of stationary contacts insulatedly mounted onsaid support means, each of said stationary contacts being positionedadjacent to and on a side of said first contact toward a respective oneof said polar structures, said magnetic circuit means having a portionthereof remote from said gap positioned in close proximity with saidpolar structure and including said gap in common with said polarstructure and providing a substantially lower reluctance flux path inshunt with said gap between one side of said gap and said armature partthan between the other side of said gap and said armature part formagnetically biasing said armature part toward said one side of saidarmature gap and normally maintaining said first contact in engagementwith one of said stationary contacts, and means for impressing amagnetomotive force on said ferromagnetic member in a direction opposedto said magnetic bias for de flecting said armature toward the otherside of said gap and to. engage said first contact with the other one ofsaid stationary contacts.

4. A polarized relay, comprising a gas-tight envelope, :1 non-magneticelectrically conductive support member extending transversely andforming an electrostatic shield in said envelope spaced from oppositeends thereof, said support member having an aperture formed therethroughand a stern portion extending from one side thereof, an elongatedferromagnetic member fixed to said stem portion and having a deflectablearmature part extending through said aperture and away from the otherside of said support member, means for producing a substantiallyconstant magnetic field and including opposed polar structures on saidother side of and supported by said support member, said polarstructures defining a gap, said defiectable armature part extending insaid gap, a first contact carried by said armature part and deflectabletherewith, a massive mounting block on the side of said polar structuresaway from said support memberand connected to the latter, a pair ofstationary contacts each insulatedly connected to said mounting blockand juxtaposed to a respective side of said first contact correspondingto one of said polar structures, magnetic circuit means including saidferromagnetic member and said polar structures providing a substantiallylower reluctance flux path in shunt with said gap between one side ofsaid gap and said armature part than between the other side of said gapand said armature part for magnetically biasing said armature parttoward said one side of said armature gap and normally maintaining saidfirst contact in engagement with one of said stationary contacts, meansfor impressing a magnetomotive force longitudinally along saidferromagnetic member opposed to the flux associated with said magneticbias and comprising an electrically conductive winding encircling saidstem portion and a portion of said ferromagnetic member whereby saidarmature part is deflected and said first contact is engaged with theother of said stationary contacts, and lead-ins sealed through saidenvelope and connected to each of said contacts and said winding.

5. A polarized relay, comprising means including opposed polarstructures juxtaposed to provide a gap and for producing a substantiallyconstant magnetic field in said gap, support means, magnetic circuitmeans including a ferromagnetic member fixed to said support means andhaving a resilient armature part extending in said gap free fordisplacement toward either of said polar structures, a first contactcarried by and movable with said armature part, a pair of stationarycontacts insulatedly mounted on said support means, each of saidstationary contacts being positioned adjacent to and on a side of saidfirst contact toward a respective one of said polar structures, saidmagnetic circuit means being adapted to magnetically bias said armaturepart toward one of said polar structures for normally maintaining saidfirst contact in engagement with one of said stationary contacts andincluding a second ferromagnetic member extending between the fixedportion of said first mentioned ferromagnetic member and the other ofsaid polar structures and forming a low reluctance magnetic couplingtherebetween, and means for impressing a magnetomotive force on saidferromagnetic member in a direction opposed to said magnetic bias fordeflecting said armature toward the other side of said gap and to engagesaid first contact with the other one of said stationary contacts.

6. A polarized relay, comprising means including opposed polarstructures juxtaposed to provide a gap and for producing a substantiallyconstant magnetic field in said gap, support means, magnetic circuitmeans including a ferromagnetic member fixed to said support means andhaving a resilient armature part extending in said gap free fordisplacement toward either of said polar structures, a first contactcarried by and movable with said armature part, a pair of stationarycontacts insulatedly mounted on said support means, each of saidstationary contacts being positioned adjacent to and on a side of saidfirst contact toward a respective one of said polar structures, saidmagnetic circuit means being adapted to magnetically bias said armaturepart toward one of said polar structures for normally maintaining saidfirst contact in engagement with one of said stationary contacts andincluding a second ferromagnetic member having one end portion connectedto the fixed portion of said first mentioned ferromagnetic member andits other end portion in close spaced relation with the other of saidpolar structures and forming a low reluctance magnetic couplingtherebetween, and means for impressing a magnetomotive force on saidferromagnetic member in a direction opposed to said magnetic bias fordeflecting said armature toward the other side of said gap and to engagesaid first contact with the other one of said stationary contacts.

7. A polarized relay comprising a gas-tight envelope, a non-magneticelectrically conductive support member extending transversely andforming an electrostatic shield in said envelope spaced from oppositeends thereof, said support member having an aperture formed therethroughand a stem portion extending from one side thereof, an elongatedferromagnetic member fixed to said stem portion amend and having adeflectable armature part extending through said aperture and away fromthe other side of said support member, means for producing asubstantially constant magnetic field and including opposed polarstructures on said other side of and supported by said support member,said polar structures defining a gap, said deflectable armature partextending in said gap, a first contact carried by said armature part anddeflectable therewith, a massive mounting block on the side of saidpolar structures away from said support member and connected to thelatter, a pair of stationary contacts each insulatedly connected to saidmounting block and juxtaposed to a respective side of said first contactcorresponding to one of said .polar structures, magnetic circuit meansincluding a second ferromagnetic member connected to the fixed endportion of said elongated ferromagnetic member and extending in closespaced relation to one of said polar structures and providing a lowreluctance flux path therebetween for magnetically biasing saidarmatureapart toward the other one of said polar structures to normallymaintain said first contact in engagement with one of said stationarycontacts, means for impressing a magnetomotive force longitudinallyalong said ferromagnetic member opposed to the flux associated with saidmagnetic bias and comprising an electrically conductive windingencircling said stem portion of said ferromagnetic member whereby saidarmature part is deflected and said first contact is engaged with theother of said stationary contacts, said winding encircling the portionof said second ferromagnetic member connected to the first mentionedferromagnetic ember with the remainder of said secondferromagneticmember extending externally of said winding, and lead-ins sealed throughsaid envelope and connected to each of said contacts and said winding.

8. A polarized relay comprising means including opposed polar structuresjuxtaposed to provide a gap and for producing a substantially constantmagnetic field in said gap, a support member having an aperture formedtherethrough and a stem portion extending from one side thereof,magnetic circuit means including an elongated resilient ferromagneticmember having one end portion thereof fixed to said stem portion and itsother end portion forming an armature part extending in said gap freefor deflection toward either of said polar structures, a first contactcarried by and movable with said armature part, a pair of stationarycontacts insulatedly mounted on said support means, each of saidstationary contacts being positioned adjacent to and on a side of saidfirst contact toward a respective one of said polar structures, saidmagnetic circuit means being adapted to magnetically bias said armaturepart toward one of said polar structures for normally maintaining saidfirst contact in engagement with one of stationary contacts andincluding a second ferromagnetic member extending between and connectedto the fixed end portion of said resilient ferromagnetic member and theother of said polar structures, and means for impressing a magnetomotive force longitudinally along said ferromagnetic member opposedto the flux associated with said magnetic bias and comprising anelectrically conductive winding encircling said stem portion and aportion of said ferromagnetic member whereby said armature part isdeflected and said first contact is engaged with the other of saidstationary contacts.

9. A polarized relay comprising a gas-tight envelope, a non-magneticelectrically conductive support member extending transversely andforming an electrostatic shield in said envelope spaced from oppositeends thereof, said support member having an aperture formed therethroughand a stem portion extending from one side thereof, an elongatedferromagnetic member fixed to said stem portion and having a deflectablearmature part extending through said aperture and away from the otherside of said support member, means for producing a substantiallyconstant magnetic field and including opposed polar structures on saidother side of and supported by said support member, said polarstructures defining a gap, said deflectable armature part extending insaid gap, a first contact carried by said armature part and deflectabletherewith, a massive mounting block-on the side of said polar structuresaway from said support member and connected to the latter, a pair ofstationary contacts each insulatedly connected to said mounting blockand juxtaposed to a respective side of said first contact correspondingto one of said polar structures, magnetic circuit means including, asecond ferromagnetic member connected to the fixed end portion of saidelongated ferromagnetic member and to one of said polar structures andproviding a low reluctance fiux path therebetween for magneticallybiasing said armature part toward the other one of said polar structuresto normally maintain said first contact in engagement with one of saidstationary contacts, means for impressing a magnetomotive forcelongitudinally along said ferromagnetic memher opposed to the fluxassociated with said magnetic bias and comprising an electricallyconductive winding encircling said stern portion and a portion of saidferromagnetic member whereby said armature part is deflected and saidfirst contact is engaged with the other of said stationary contacts, andlead-ins sealed through said envelope and connected to eachof saidcontacts, and said winding.

10. A polarized relay, comprising means including opposed polarstructures juxtaposed to provide a gap and for producing a substantiallyconstant magnetic field in said gap, magnetic circuit means independentof said first mentioned means and including a ferromagnetic memberhaving a deflectable armature part extending in said gap fordisplacement therein, a firstcontact carried by and deflectable withsaid armature part, a pairof stationary contacts each positionedadjacent to and on a side of said first contact toward a respective oneof said polar structures, said magnetic circuit means having a portionthereof remote from said gappositioned in close proximity with saidpolar structure and including said gap in common withsaid polarstructure andproviding a flux path extending along said ferromagneticmember in shunt with said. gap, means supporting said ferromagneticmember with the armature part thereof substantially more closely spacedwith-respect to-one of said polar structures as compared to the other inthe absence of any magnetic fiux, whereby said magnetic circuit meansshunts the flux path across said gap asymmetrically, said constantmagnetic field serving to deflect said armature toward said one polarstructure and normally maintain said first contact in engagement withone of said stationarycontacts, and means for producing electromagneticfield flux along said ferromagnetic member in a direction opposed to theflux of said constant magnetic field along said shunt path fordeflecting said armature part toward the other one of said polarstructures to engage said first contact with the other one of saidstationary contacts.

11. A polarized relay, comprising means including opposed polarstructures juxtaposed to provide a gap and for producing a substantiallyconstant magnetic field in said gap, support means on one side of saidpolar structures, magnetic circuit means independent of said firstmentioned means and including a ferromagnetic member fixed to saidsupport means on the side thereof away from said polar structures andhaving a resilient armature part extending in said gap free fordisplacement toward either of said polar structures, a first contactmovable with said armature part, a pair of stationary contactsinsulatedly mounted on said support means, each of said stationarycontacts being positioned adjacent to and on a side of said firstcontact toward a respective one of said polar structures, saidferromagnetic member being positioned so that in the absence of magneticflux said armature part is substantially more closely spaced to one ofsaid polar structures as compared to the other, said magnetic circuitmeans having a portion thereof remote from said gap positioned in closeproximity with said polar structure and including said gap in commonwith said polar structure and providing a flux path including saidferromagnetic member in shunt with said gap with magnetomotive forcedeveloped by said constant magnetic field normally maintaining saidfirst contact in engagement with one of said stationary contacts, andmeans for producing electromagnetic field flux along said ferromagneticmember opposed to the flux of said constant magnetic field along saidshunt path for deflecting said armature part toward the other one ofsaid polar structures to engage said first contact with the other one ofsaid stationary contacts.

12. A polarized relay, comprising means including opposed polarstructures juxtaposed to provide a gap and for producing a substantiallyconstant magnetic field in said gap a support member on one side of saidpolar structures having an aperture formed therethrough and a stemportion extending from one side thereof away from said polar structures,magnetic circuit means including an elongated resilient ferromagneticmember having one end portion thereof fixed to said stem portion and itsother end portion forming an armature part extending in said gap freefor deflection toward either of said polar structures, a first contactcarried by and movable with said armature part, a pair of stationary contacts insulatedly mounted on said support means, each of said stationarycontacts being positioned adjacent to and on a side of said firstcontact toward a respective one of said polar structures, thelongitudinal axis of the fixed portion of said ferromagnetic memberbeing offset from the corresponding mutual axis of said polarstructures, toward one of said polar structures, said magnetic circuitmeans including a second ferromagnetic member extending between thefixed portion of the residual ferromagnetic member and the other of saidpolar structures so that said armature part is magnetically biasedtoward said one of said polar structures for normally maintaining saidfirst contact in engagement with one of said stationary contacts, andmeans for impressing a magnetomotive force longitudinally along saidferromagnetic member opposed to the flux associated with said magneticbias and comprising an electrically conductive winding encircling saidstem portion and a portion of said ferromagnetic member whereby saidarmature part is deflected and said first contact is engaged with theother of said stationary contacts.

13. A polarized relay, comprising a gas-tight envelope,

a non-magnetic electrically conductive support member extendingtransversely and forming an electrostatic shield in said envelope spacedfrom opposite ends thereof, said support member having an apertureformed therethrough and a stern portion extending from one side thereof,an elongated ferromagnetic member fixed to said stem portion and havinga deflectable armature part extending through said aperture and awayfrom the other side of said support member, means for producing asubstantially constant magnetic field and including opposed polarstructures on said other side of and supported by said support member,said polar structures defining a gap, said defiectable armature partextending in said gap, at first contact carried by said armature partand deflectable therewith, a massive mounting block on the side of saidpolar structures away from said support member and connected to thelatter, a pair of stationary contacts each insulatedly connected to saidmounting block and juxtaposed to a respective side of said first contactcorresponding to one of said polar structures, the longitudinal axis ofthe fixed portion of said ferromagnetic member being offset from thecorresponding mutual axis of said polar structures so that said armatureis magnetically biased toward one of said polar structures for normallymaintaining said first contact in engagement with one of said stationarycontacts, means for impressing a magnetomotive force longitudinallyalong said ferromagnetic member opposed to the flux associated With saidmagnetic bias and comprising an electrically conductive windingencircling said stem portion and a portion of said ferromagnetic memberwhereby said armature part is deflected and said first contact isengaged with the other of said stationary contacts, and a plurality oflead-ins sealed through said envelope with one connected to each of saidcontacts and to each end of said winding.

References Cited in the file of this patent UNITED STATES PATENTS2,056,745 Stalnaker Oct. 6, 1936 FOREIGN PATENTS 2,654 Great BritainJuly 1, 1879 of 1879 491,893 Great Britain Sept. 12, 1938 984,780 FranceFeb. 28, 1951

